System and method for measuring saturated steam flow using redundant measurements

ABSTRACT

A system and method for measuring a flow of saturated steam can include a temperature sensor that measures process temperature, and one or more pressure sensors that measure pressure including differential pressure and static pressure. A flow of saturated steam can be calculated from two sets of measurements, one measurement using the differential pressure and the static pressure and a second measurement using the differential pressure and the process temperature. Redundant flow measurements can be provided with respect to the flow of saturated steam in case of failure of the temperature sensor or the pressure sensors. In addition, a deviation between the flow of the saturated steam as calculated from the process temperature and the differential pressure compared to a flow of saturated steam as calculated from the differential pressure and the static pressure can provide an indication of degradation of the temperature sensor or the pressure sensors.

TECHNICAL FIELD

Embodiments are generally related to devices and systems that measurethe flow of a fluid, and in particular, the flow of saturated steam.Embodiments also relate to flow measuring systems and multi-variabletransmitters used in flow measuring systems.

BACKGROUND

Industrial multi-variable transmitters can be used to measure the flowof a fluid. Measuring the flow of saturated steam is a specificapplication where multi-variable transmitters can be used.Multi-variable transmitters offer a less expensive alternative comparedto other measuring technologies (e.g., vortex flowmeters).

Sensors may degrade or fail over time due to the effects (e.g.,pressures and temperatures) of the process fluids and the environmentsin which they are used for industrial applications. When a sensordegrades, the calculated flow error can increase. When the sensor fails,the calculated flow may not be available. When the calculated flowoutput is not available or not current, the other applications that relyon the sensor can be adversely affected, whether for control, inventorymanagement, or other purposes.

BRIEF SUMMARY

The following summary is provided to facilitate an understanding of someof the features of the disclosed embodiments and is not intended to be afull description. A full appreciation of the various aspects of theembodiments disclosed herein can be gained by taking the specification,claims, drawings, and abstract as a whole.

It is, therefore, one aspect of the disclosed embodiments to provide foran improved flow measuring system and method.

It is another aspect of the disclosed embodiments to provide an improvedmulti-variable transmitter for use in measuring the flow of a fluid andin particular saturated steam flow.

It is another aspect of the disclosed embodiments to provide for a flowmeasuring system and method that operates with a degree of measurementredundancy in the event of a failure of one or more sensors.

It is a further aspect of the disclosed embodiments to provide for earlysensor warning diagnostics for a flow measuring system based on acalculated deviation.

The aforementioned aspects and other objectives can now be achieved asdescribed herein.

In an embodiment, a system for measuring a flow of saturated steam, caninclude a temperature sensor that measures a process temperature, and atleast one pressure sensor that measures pressure including adifferential pressure and a static pressure, wherein two sets ofmeasurements can be used to calculate a flow of saturated steam, whereina first set of measurements among the two sets of measurements uses thedifferential pressure and the static pressure to calculate the flow ofsaturated steam and a second set of measurements among the sets ofmeasurements uses the differential pressure and the process temperatureto calculate the flow of saturated steam. The system can be configuredto provide redundant flow measurements with respect to the flow of thesaturated steam in case of a failure of either the temperature sensor orthe static pressure sensor.

In an embodiment, a deviation between a flow of the saturated steam ascalculated from the process temperature and the differential pressurecompared to a flow of the saturated steam as calculated from thedifferential pressure and the static pressure can provide an indicationof a degradation of at least one of: the temperature sensor and the atleast one pressure sensor.

In an embodiment, the deviation can comprise an early indicator forcalibration of either the temperature sensor or the at least onepressure sensor.

In an embodiment, a quality status regarding which of the redundant flowmeasurements can be output with respect to the flow of the saturatedsteam.

In an embodiment a quality status can be output regarding at least oneof the differential pressure and the process temperature measured tocalculate the flow of the saturated steam, and the differential pressureand the static pressure measured to calculate the flow of the saturatedsteam.

In an embodiment, the system can include at least one of amulti-variable transmitter, a field mounted device, an RTU (RemoteTerminal Unit), a PLC (Programmable Logic Controller), and a DCS(Distributed Control System).

In an embodiment, a system for measuring a flow of saturated steam, caninclude at least one processor, and a non-transitory computer-usablemedium embodying computer program code, the computer-usable mediumcapable of communicating with the at least one processor. The computerprogram code can include instructions executable by the at least oneprocessor and configured for: measuring a process temperature with atemperature sensor, and measuring with at least one pressure sensor, apressure including a differential pressure and a static pressure,wherein two sets of measurements are used to calculate a flow ofsaturated steam, wherein a first set of measurements among the two setsof measurements uses the differential pressure and the static pressureto calculate the flow of saturated steam and a second set ofmeasurements among the sets of measurements uses the differentialpressure and the process temperature to calculate the flow of saturatedsteam, wherein the system is configured to provide redundant flowmeasurements with respect to the flow of the saturated steam in case ofa failure of either the temperature sensor or the static pressuresensor.

In an embodiment, the instructions can be further configured fordetermining a deviation between a flow of the saturated steam ascalculated from the process temperature and the differential pressurecompared to a flow of the saturated steam as calculated from thedifferential pressure and the static pressure provides an indication ofa degradation of at least one of: the temperature sensor and the atleast one pressure sensor.

In an embodiment, a method for measuring a flow of saturated steam, caninclude the steps of measuring a process temperature with a temperaturesensor, and measuring with at least one pressure sensor, a pressureincluding a differential pressure and a static pressure, wherein twosets of measurements are used to calculate a flow of saturated steam,wherein a first set of measurements among the two sets of measurementsuses the differential pressure and the static pressure to calculate theflow of saturated steam and a second set of measurements among the setsof measurements uses the differential pressure and the processtemperature to calculate the flow of saturated steam. Redundant flowmeasurements are thus provided with respect to the flow of the saturatedsteam in case of a failure of either the temperature sensor or thestatic pressure sensor.

In an embodiment, the method can further include the step of determininga deviation between a flow of the saturated steam as calculated from theprocess temperature and the differential pressure compared to a flow ofthe saturated steam as calculated from the differential pressure and thestatic pressure provides an indication of a degradation of at least oneof: the temperature sensor and the at least one pressure sensor.

In an embodiment of the method, the deviation can comprise an earlyindicator for calibration of either the temperature sensor or the atleast one pressure sensor.

In an embodiment, the method can further include the step of generatinga quality status regarding which of the redundant flow measurements isoutput with respect to the flow of the saturated steam.

In an embodiment, the method can further include the step of generatinga quality status regarding the differential pressure and the processtemperature measured to calculate the flow of the saturated steam.

In an embodiment, the method can further include the step of generatinga quality status regarding the differential pressure and the staticpressure measured to calculate the flow of the saturated steam.

In an embodiment, the method can further include the step of generatinga quality status regarding at least one of: the differential pressureand the process temperature measured to calculate the flow of thesaturated steam; and the differential pressure and the static pressuremeasured to calculate the flow of the saturated steam.

In an embodiment, the method can further include the step of measuringthe process temperature with the temperature sensor, the step ofmeasuring with the at least one pressure sensor, the pressure includingthe differential pressure and the static pressure, and the step ofdetermining the deviation between the flow of the saturated steam ascalculated from the process temperature and the differential pressurecompared to the flow of the saturated steam as calculated from thedifferential pressure and the static pressure to provide an indicationof the degradation of at least one of the temperature sensor and the atleast one pressure sensor, can be performed in least of one of: amulti-variable transmitter, a field mounted device, an RTU (RemoteTerminal Unit), a PLC (Programmable Logic Controller), and a DCS(Digital Control System).

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying figures, in which like reference numerals refer toidentical or functionally-similar elements throughout the separate viewsand which are incorporated in and form a part of the specification,further illustrate the present invention and, together with the detaileddescription of the invention, serve to explain the principles of thepresent invention.

FIG. 1 illustrates a pictorial diagram of a system for measuring flow inaccordance with an embodiment;

FIG. 2 illustrates a flow diagram depicting logical operational steps ofa method of operating a multi-variable transmitter in a system formeasuring flow, in accordance with an embodiment;

FIG. 3 illustrates a flow diagram depicting additional logicaloperational steps of a method of operating a multi-variable transmitterin a system for measuring flow, in accordance with an embodiment;

FIG. 4 illustrates a flow diagram depicting further logical operationalsteps of a method of operating a multi-variable transmitter in a systemfor measuring flow, in accordance with an embodiment;

FIG. 5 illustrates a block diagram depicting aspects of a system formeasuring flow including a multi-variable transmitter, in accordancewith an embodiment;

FIG. 6 illustrates a block diagram depicting aspects of a system formeasuring flow including a multi-variable transmitter, in accordancewith an alternative embodiment; and

FIG. 7 illustrates a block diagram depicting aspects of a system formeasuring flow including a multi-variable transmitter, in accordancewith another embodiment.

DETAILED DESCRIPTION

The particular values and configurations discussed in these non-limitingexamples can be varied and are cited merely to illustrate one or moreembodiments and are not intended to limit the scope thereof.

Subject matter will now be described more fully hereinafter withreference to the accompanying drawings, which form a part hereof, andwhich show, by way of illustration, specific example embodiments.Subject matter may, however, be embodied in a variety of different formsand, therefore, covered or claimed subject matter is intended to beconstrued as not being limited to any example embodiments set forthherein; example embodiments are provided merely to be illustrative.Likewise, a reasonably broad scope for claimed or covered subject matteris intended. Among other issues, subject matter may be embodied asmethods, devices, components, or systems. Accordingly, embodiments may,for example, take the form of hardware, software, firmware, or acombination thereof. The following detailed description is, therefore,not intended to be interpreted in a limiting sense.

Throughout the specification and claims, terms may have nuanced meaningssuggested or implied in context beyond an explicitly stated meaning.Likewise, phrases such as “in one embodiment” or “in an exampleembodiment” and variations thereof as utilized herein may notnecessarily refer to the same embodiment and the phrase “in anotherembodiment” or “in another example embodiment” and variations thereof asutilized herein may or may not necessarily refer to a differentembodiment. It is intended, for example, that claimed subject matterinclude combinations of example embodiments in whole or in part.

In general, terminology may be understood, at least in part, from usagein context. For example, terms such as “and,” “or,” or “and/or” as usedherein may include a variety of meanings that may depend, at least inpart, upon the context in which such terms are used. Generally, “or” ifused to associate a list, such as A, B, or C, is intended to mean A, B,and C, here used in the inclusive sense, as well as A, B, or C, hereused in the exclusive sense. In addition, the term “one or more” as usedherein, depending at least in part upon context, may be used to describeany feature, structure, or characteristic in a singular sense or may beused to describe combinations of features, structures, orcharacteristics in a plural sense. Similarly, terms such as “a,” “an,”or “the”, again, may be understood to convey a singular usage or toconvey a plural usage, depending at least in part upon context. Inaddition, the term “based on” may be understood as not necessarilyintended to convey an exclusive set of factors and may, instead, allowfor existence of additional factors not necessarily expressly described,again, depending at least in part on context.

Some multi-variable transmitters can measure differential pressure (DP)and static pressure (SP) to calculate the flow of saturated steam (thismethod will be referred to as “Option A” in this disclosure). Othermulti-variable transmitters can measure differential pressure (DP) andprocess temperature (PT) to calculate the flow of saturated steam (thisapproach will be referred to as “Option B” in this disclosure). Somemulti-variable transmitters allow a user to select either Option A orOption B to calculate the saturated steam flow. Other multi-variabletransmitters may only support one of these two options due to thesensors used. In Option A, if the SP sensor degrades or fails, thecalculated flow output may be either less accurate or unavailable,respectively. In Option B, if the PT sensor degrades or fails, thecalculated flow output may be either less accurate or unavailable,respectively.

FIG. 1 illustrates a pictorial diagram of a system 100 for measuringflow, which can be configured to include a multi-variable transmitter114, in accordance with an embodiment. The multi-variable transmitter114 of the system 100 depicted in FIG. 1 can be utilized to measure theflow of a fluid, and in particular, the flow of saturated steam. Themulti-variable transmitter 114 can include a temperature sensor 112(e.g., a PT sensor), which may be, for example, an RTD (ResistanceTemperature Detector) sensor, or a TIC (Thermocouple), thermocouple andRTD sensor, and can be of any IEC standard sensor or GOST standardsensor. The multi-variable transmitter 114 can further include apressure meter body 118, a three valve-manifold 110, a first valve 104,a second valve 102, and a third valve 106.

As will be discussed in further detail herein, one or more pressuresensors can be located within the pressure meter body 118. In anembodiment, the pressure meter body 118 can contain one or morepressures sensors, such as an SP (Static Pressure) sensor and a DP(Differential Pressure) sensor. In another embodiment, a single pressuresensor can be implemented in the pressure meter body 118, which measuresboth SP and DP. FIG. 5 , for example, depicts a DP sensor 119 and an SPsensor 121 contained within the pressure meter body 118. FIG. 6 , forexample, depicts a single DP/SP sensor 123 contained within the pressuremeter body 118.

In either case, a pressure sensor contained within the pressure meterbody 118 can be configured to measure the pressure of a fluid, which canassist in providing an indication of the flow of saturated steam. Such apressure sensor can be a differential pressure sensor and a staticpressure sensor, and can comprise a diaphragm-based piezoresistive,capacitance, or other known type of pressure sensor.

Note that an RTD sensor is a type of temperature sensor that can containa resistor that changes resistance value as its temperature changes. AT/C sensor is a type of temperature sensor based on a thermocouple thatincludes at least two dissimilar electrical conductors that formelectrical junctions at different temperatures. A thermocouple canproduce a temperature-dependent voltage as a result of thethermoelectric effect, and this voltage can be interpreted to measuretemperature in the context of a T/C sensor. An RTD sensor or a T/Csensor can be any type of IEC (International ElectrotechnicalCommission) standard sensor or GOST standard sensor. It should beappreciated that the disclosed embodiments are not limited to thesespecific types of temperature sensors, and that the aforementionedtemperature sensor types are discussed herein for exemplary purposesonly.

The system 100 can further include process connections 120 that caninterface to both a high-pressure side and a low-pressure side of thepressure meter body 118. The multi-variable transmitter 114 can connectto a host system via a wired interface (e.g., with communicationsprotocols such as HART (Highway Addressable Remote Transducer),FOUNDATION™ Fieldbus, or MODBUS®) or a wireless interface (e.g., such asISA 100 or Wireless HART).

As utilized herein, HART or “Highway Addressable Remote Transducer”relates to a communication standard used in the process controlindustry, and can be referred to as the HART communication protocol, theHART protocol or simply HART. The HART protocol can support a combineddigital and analog signal on a dedicated wire or set of wires, in whichonline process signals (e.g., such as control signals, sensormeasurements, etc.) an be provided as an analog current signal (e.g.,ranging from 4 to 20 milliamps) and in which other signals, such asdevice data, requests for device data, configuration data, alarm andevent data, etc., can be provided as digital signals superimposed ormultiplexed onto the same wire or set of wires as the analog signal.

The term FOUNDATION™ Fieldbus as utilized herein relates to theFoundation Fieldbus specification, which is an all-digital, serialtwo-way communications system that can server a base-level network in aplant or factory automation environment. FOUNDATION™ Fieldbus is an openarchitecture, developed and administered by FieldComm Group™. Note thatFIELDBUS FOUNDATION™ and FOUNDATION™ are trademarks of the FieldbusFoundation, which is responsible for the definition of the FoundationFieldbus specification.

The term “MODBUS® as utilized herein relates to a digital communicationsprotocol that allows controllers and devices (e.g., field devices) fromdifferent manufacturers to exchange data using standard formats. TheMODBUS® protocol (also referred to simply as “Modbus”) can define amessage structure that controllers and other devices can recognize anduse regardless of the types of networks over which they communicate—mosttypically RS-485 serial or Ethernet using TCP.

Note that the term “ISA 100” as utilized herein refers to a standarddefining wireless systems for industrial automation and controlapplications including variations thereof (e.g., ISA100.11a, etc)released by the ISA (International Society of Automation).

The term “wireless HART” (also referred to as WirelessHART) as utilizedherein can relate to a wireless mesh network communications protocol forprocess automation applications, which can add wireless capabilities tothe wired HART protocol while maintaining compatibility with existingwired HART-enabled devices, commands and tools. A WirelessHART networkcan use, for example, IEEE 802.15.4 compatible radios operating in the2.4 GHz radio band. Each device in a WirelessHART mesh network can serveas a router for messages from other devices. In other words, a devicedoes not have to communicate directly to a gateway, but just forward itsmessage to the next closest devices. This feature can extend the rangeof the WirelessHART network and provide redundant communications routesthat increase network reliability.

The system 100 can further include a flow tube 108 through which a fluidflows in a direction indicated by arrow 109. The multi-variabletransmitter 114 can further include a communications interface 116(i.e., wireless or wired) to the host system. The pressure meter body118 can contain both an SP sensor and a DP sensor. The flow tube 108 maybe a fluid pipe or other process connection. The communicationsinterface 116 can be implemented as an electronic circuit, which may bedesigned to a specific communications standard, which can allow one ormore machines, devices or systems to telecommunication with one or moreother machines, devices or systems.

The host system may be an industrial process control and automationsystem, and can include various components that facilitate production orprocessing of at least one product or other material. An industrialprocess control and automation system can be used to facilitate controlover components in one or multiple plants including processingfacilities and manufacturing facilities for producing at least oneproduct or other material. In general, the host system may implement oneor more processes and can be referred to as a process system. A processsystem generally represents any system or portion thereof configured toprocess one or more products or other materials in some manner.

As discussed previously, some multi-variable transmitters measuredifferential pressure and static pressure to calculate the flow ofsaturated steam. This approach will be referred to as “Option A” in thisdisclosure. Other multi-variable transmitters may measure differentialpressure and process temperature to calculate the flow of saturatedsteam. This approach will be referred to as “Option B” in thisdisclosure. Some multi-variable transmitters allow a user to selecteither Option A or B to calculate the saturated steam flow. In Option A,however, if the SP sensor degrades or fails, the calculated flow outputmay be either less accurate or unavailable, respectively. In Option B,if the PT sensor degrades or fails, the calculated flow output may beeither less accurate or unavailable, respectively.

FIG. 2 illustrates a flow diagram depicting logical operational steps ofa method 200 of operating the multi-variable transmitter 114, inaccordance with an embodiment. A legend 198 shown in the lower left handside of FIG. 2 includes a summary of various acronyms and terms, such asSP (Static Pressure), DP (Differential Pressure), PT (ProcessTemperature), and Option A and Option B as discussed previously. Asindicated at block 206, a measurement cycle can begin with respect tothe multi-variable transmitter 114. In the disclosed approach, thesaturated steam flow is calculated from two sets of measurements, oneusing the differential pressure and static pressure and the secondmeasurement using the differential pressure and process temperature. Thesystem 100 is configured to provide redundant flow measurements withrespect to the flow of the saturated steam in case of a failure ofeither the temperature sensor or the static pressure sensor.

During the measurement cycle, the SP can be measured and a statusobtained, as shown at block 208. The DP can also be measured and astatus obtained, as shown at block 210. The PT can also be measured anda status obtained, as shown as block 212. Thereafter, as shown at block214, Option A can be implemented in which the flow and status arecomputed as a function of DP and SP (i.e. Flow=fn (DP, SP)). As depictedat block 216, Option B can be implemented, wherein flow and status arecomputed as a function of DP and PT (i.e. Flow=fn (DP, PT)).

Next, as illustrated at block 218, a step or operation can beimplemented in which the flow (or FLOW) value and status are evaluated.Thereafter, as shown at block 220, a step or operation can beimplemented in which a deviation value and status are evaluated.Thereafter, as shown at block 222, the measurement cycle can terminate.

FIG. 3 illustrates a flow diagram depicting additional logicaloperational steps of a continuation of the method 200 of operating themulti-variable transmitter 114, in accordance with an embodiment. Thesteps or operations shown in FIG. 3 are associated with the evaluateFLOW and status operation shown at block 218 in FIG. 2 . The legend 237shown in FIG. 3 is similar to the legend 198 shown in FIG. 2 . FIG. 3thus represents a more detailed view of the operation depicted at block218 in FIG. 3 .

As shown at block 219 in FIG. 3 , data can be obtained and arranged in atable that represents a decision that a method (e.g., an algorithm) canuse to determine the best flow value, as a part of the evaluate FLOWvalue and status operation associated with block 218. Once such data isaccumulated and analyzed, a FLOW value and status can be written as partof a ‘write’ operation, as shown at block 236.

FIG. 4 illustrates a flow diagram depicting further logical operationalsteps of a method 240 of operating a multi-variable transmitter, inaccordance with an embodiment. The steps or operations shown in thevarious blocks in FIG. 4 present a more detailed view of the evaluatedeviation value and status operation associated with block 220. Thus, asindicated at decision block 224, a step or operation can be implementedto determine if the flow status is “bad”. If the answer is “Yes”, thenas shown at block 226 an operation can be implemented wherein “SetDEV=NaN” (Not a Number) and “Set DEV_STAT=Bad”. Thereafter, thedeviation value and status can be written, as shown at block 236. Notethat “DEV” represents the term “deviation”.

Assuming the answer with respect to decision block 224 is “No”, then astep or operation can be implemented as indicated at block 228 wherein“Set DEV=ABS(OPT_A−OPT_B)”. That is, a deviation can be found which isequivalent to the absolute value of the difference between the Option Aand Option B results (i.e., OPT_A represents Option A and OPT_Brepresents Option B). Next, as shown at decision block 230, a step oroperation can be implemented to determine if the deviation is greaterthan deviation limit. If yes, then as indicated at block 232, a step oroperation can be implemented wherein “Set DEV_STAT=INLIMIT” followed bythe write deviation value and status operation shown at block 236.Assuming that the answer with respect to the decision block 230 is “No”,then a step or operation can be implemented as depicted at block 234wherein “Set DEV_STAT=OVERLIMIT”. Thereafter, the write DEV value andstatus operation can be implemented as shown at block 236.

The approach described above can leverage both Option A and Option B toprovide a degree of measurement redundancy in the event to failure byeither the PT sensor or the SP sensor. Since Option A and Option B bothuse DP, the disclosed approach should have a good DP measurement. Notethat the temperature sensor 112 is not located in the pressure meterbody 118. Only the SP sensor and the DP sensor are located in thepressure meter body 118.

A check for a deviation between the Option A calculation and the OptionB calculation can be implemented to report early sensor warningdiagnostics for the multi-variable transmitter 114. In addition, thedisclosed approach can be used to maintain a current and accurate flowoutput in cases when either the temperature sensor 112 or SP sensorfails. Additionally, the disclosed approach can be implemented for earlydetection of degrading sensors, and also offers a less expensivealternative to vortex flowmeters or other more expensive flowmeters.

FIG. 5 illustrates a block diagram depicting aspects of the system 100including the multi-variable transmitter 114, in accordance with anembodiment. As shown in FIG. 5 , the multi-variable transmitter 114 caninclude a data-processing apparatus 400 that includes a processor 341, amemory 342, and a display 346. It can be appreciated that additionalcomponents may be included in data-processing apparatus 400 as may beneeded. The processor 341 may be implemented as a microprocessor or amicrocontroller or a combination of both a microprocessor and amicrocontroller. The memory 342 can include a volatile memory or anon-volatile memory or a combination of a volatile memory and anon-volatile memory. For example, memory 342 may be implemented as not asingle memory component but two or more memory devices or memorycomponents. The display 346 can be implemented as a small display with,for example, several pushbuttons.

As discussed previously herein, the flow measuring system 100 caninclude a pressure meter body 118 that can contain one or more pressuresensors. As shown in the example embodiment depicted in FIG. 5 , thepressure meter body 118 can contain both a DP sensor 119 and an SPsensor 121. The flow measuring system 100 additionally can include thetemperature sensor 112, as discussed previously herein.

The processor 341 can access pressure data and temperature data storedin the memory 342. The processor 341 can receive an output from the DPsensor 119, an output from the SP sensor and an output from thetemperature sensor 112. Although not shown, in some embodiments ananalog-to-digital converter (ADC) can be located between the output ofthe DP sensor 119, an output from the SP sensor, and an output of thetemperature sensor 112 and provide a digital signal to digitalcomponents such as processor 341 or other devices. Likewise, in otherembodiments, a digital-to-analog converter (DAC) may be located betweenthe output of processor 341 and the multi-variable transmitter 114 ifthe multi-variable transmitter 114 comprises an analog output.

It should be appreciated that the temperature sensor 112, the DP sensor119 and the SP sensor 121 are not inherently redundant. In essence, thedisclosed embodiments use three (e.g., PT, SP, DP) sensors that are notin themselves redundant, but by way of the disclosed method, cancalculate the saturated steam flow in two ways as discussed herein,thereby providing redundancy for the flow output from the transmitter toits host system. Additionally, the deviation between the flow ofsaturated steam as calculated from the process temperature and thedifferential pressure compared to the flow of saturated steam ascalculated from the differential pressure and static pressure canindicate a degradation of one or more of these sensors (e.g.,temperature sensor 112 or SP sensor 121).

FIG. 6 illustrates a block diagram depicting aspects of the system 100including the multi-variable transmitter 114, in accordance with analternative embodiment. The configuration shown in FIG. 6 is similar tothe arrangement shown in FIG. 5 , with the difference being that FIG. 6depicts a single pressure sensor that can function as a DP sensor and anSP sensor (i.e., see the DP/SP sensor 123) rather than the separate DPsensor 119 and the separate SP sensor 121 shown in FIG. 5 .

It should be appreciated that although a preferred embodiment can beexecuted in the context of the multi-variable transmitter 114, thedisclosed approach can be executed in other devices, such as, forexample, an external control computer associated with a host system, aflow computer that is implemented as a field mounted device, and/or inother devices such as an RTU (Remote Terminal Unit), a PLC (ProgrammableLogic Computer), and a DCS (Digital Control System).

FIG. 7 illustrates a block diagram depicting aspects of the system 100for measuring flow including the multi-variable transmitter 114, thepressure meter body 118 (which includes the DP/SP sensor 123), and thetemperature sensor 112, in accordance with another embodiment. In theembodiment shown in FIG. 7 , the disclosed approach can be implementedin the context of another computing system 302, which is located remotefrom the system 100, and which can communicate with the multi-variabletransmitter 114 through a network 300. The computing system 302 can be,for example, a control system or control computer, which can store in amemory and/or process the various steps, operations or instructions,described herein, and can remotely control the operations and functionsof system 100 including its various components such as themulti-variable transmitter 114.

In some embodiments, the network 300 may be a “cloud” network or anothertype of network (e.g., such as the HART-type networks—wirelesses orwired—that were previously discussed herein). Note that the term cloudnetwork as utilized herein relates to a network based on “cloudcomputing” which refers to the on-demand availability of computer systemresources, particularly data storage and computing power, without thedirect active management by a user.

The term “cloud computing” and hence a “cloud network” can be used todescribe data centers available to many users over the Internet. Largeclouds, predominant today, often have functions distributed overmultiple locations from central servers. If the connection to the useris relatively close, it may be designated an edge server, which is anexample of an edge device. A “cloud” or “cloud network” may be limitedto a single organization (enterprise clouds,) be available to manyorganizations (public cloud,) or a combination of both (hybrid cloud).

Note that the term “edge device” as used herein can refer to a devicethat provides an entry point into an enterprise or service provider corenetworks. Examples include routers, routing switches, integrated accessdevices (IADs), multiplexers, and a variety of metropolitan area network(MAN) and wide area network (WAN) access devices.

The disclosed embodiments can be deployed in a number of differentcontexts and environments. As discussed previously, the disclosedapproach can be implemented and run in the multi-variable transmitter114. Running the disclosed method in the multi-variable transmitter 114can result in a fast evaluation and flow calculation for a singlemulti-variable transmitter. A trade-off, however, is that this approachmay require processing at the lowest level computing engine.

The disclosed approach can alternatively be deployed in the context ofan edge device or a data aggregator. An advantage of this type ofdeployment is that an evaluation for multiple-variable transmitters canbe implemented in a given locale. A trade-off in this deployment is aless frequent sampling rate compared to an on-board multi-variabletransmitter implementation.

Another potential deployment of the disclosed approach involves anon-premise monitoring system. An advantage of this approach is that anevaluation for multiple multi-variable transmitters can be implementedin multiple locales. A trade-off, however, that may be inherent withthis type of deployment, is a less frequent sampling rate as compared toan on-board multi-variable transmitter deployment or an edge devicedeployment.

Another type of deployment of the disclosed approach can involveoff-premise or cloud monitoring systems (e.g., see the prior discussionregarding “cloud computing”). An advantage of this deployment type isthat evaluations can be performed for multi-variable transmitters acrossan enterprise or organization. A trade-off for this type of scenario isthat this deployment is dependent on a reliable connection from theoff-premise/cloud to the edge device.

It should be further appreciated that the order of the various steps,operations and instructions shown at the various blocks in FIGS. 1-7herein can be arranged or implemented in a different order or with feweror more steps, operations and instructions or elements. In other words,the particular ordering of elements shown in FIGS. 1-7 is not a limitingfeature of the disclosed embodiments.

As can be appreciated by one skilled in the art, example embodiments canbe implemented in the context of a method, data-processing system, orcomputer program product. The disclosed embodiments can be implementedin for example, an external device or data-processing system (e.g., acomputer) or in the multi-variable transmitter 114 itself as shown inthe embodiments depicted in FIGS. 5-7 . Accordingly, some embodimentsmay take the form of a hardware embodiment, a software embodiment or anembodiment combining software and hardware aspects generally referred toherein as a “module.” Furthermore, embodiments may in some cases takethe form of a computer program product on a computer-usable storagemedium having computer-usable program code embodied in the medium. Anysuitable computer readable medium may be utilized including hard disks,USB Flash Drives, DVDs, CD-ROMs, optical storage devices, magneticstorage devices, server storage, databases, and so on.

Computer program code for carrying out operations of the presentinvention may be written in an object oriented programming language(e.g., Java, C++, etc.). The computer program code, however, forcarrying out operations of particular embodiments may also be written inprocedural programming languages, such as the “C” programming languageor in a visually oriented programming environment, such as, for example,Visual Basic.

The program code may execute on the user's computer, partly on theuser's computer, as a stand-alone software package, partly on the user'scomputer and partly on a remote computer or entirely on the remotecomputer. In the latter scenario, the remote computer may communicatewith the multi-variable transmitter 114, for example, through thenetwork 300, which may be a network such as a LAN (Local Area Network),WAN (Wide Area Network), or a wireless data network (e.g., Wi-Fi, Wimax,802.xx, and cellular network) or the connection may be made to anexternal computer via most third party supported networks (for example,through the Internet utilizing an Internet Service Provider).

The disclosed example embodiments are described at least in part hereinwith reference to flowchart illustrations and/or block diagrams ofmethods, systems, and computer program products and data structuresaccording to embodiments of the invention. It will be understood thateach block of the illustrations, and combinations of blocks, can beimplemented by computer program instructions. These computer programinstructions may be provided to a processor of, for example, ageneral-purpose computer, a special-purpose computer, or anotherprogrammable data processing apparatus to produce a machine, such thatthe instructions, which execute via the processor of the computer orother programmable data processing apparatus, can create a device orsystem for implementing the functions/acts specified in the block orblocks.

To be clear, the disclosed embodiments can be implemented in the contextof, for example a special-purpose computer or a general-purposecomputer, or other programmable data processing apparatus or system. Forexample, in some example embodiments, a data processing apparatus orsystem can be implemented as a combination of a special-purpose computerand a general-purpose computer.

In a preferred embodiment, the disclosed method can be run in thecontext of the multi-variable transmitter 114. In some cases, however,an external control system that includes an external computing device orcomputing system can use signals transmitted from the multi-variabletransmitter 114 to control the setting and operations of the system 100and the multi-variable transmitter 114, along with control of thevarious sensing devices such as the DP sensor 119, the SP sensor 121,the temperature sensor 112 and so on. A control computer associated witha host system, for example, located remote from the system 100 maycommunicate with the multi-variable transmitter 114 via, for example,the communications interface 116 (i.e., wireless or wired) discussedpreviously.

The aforementioned computer program instructions may also be stored in acomputer-readable memory (e.g., such as memory 342 or in another memorysuch as a memory of a server or control computer associated with a hostsystem) that can direct a computer or other programmable data processingapparatus to function in a particular manner, such that the instructionsstored in the computer-readable memory produce an article of manufactureincluding instruction means which implement the function/act specifiedin the various block or blocks, flowcharts, and other architectureillustrated and described herein.

The computer program instructions may also be loaded onto a computer orother programmable data processing apparatus to cause a series ofoperational steps to be performed on the computer or other programmableapparatus to produce a computer implemented process such that theinstructions which execute on the computer or other programmableapparatus provide steps for implementing the functions/acts specified inthe various blocks disclosed herein.

The flowchart and block diagrams in the figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s).

In some alternative implementations, the functions noted in the blocksmay occur out of the order noted in the figures. For example, two blocksshown in succession may, in fact, be executed concurrently, or theblocks may sometimes be executed in the reverse order, depending uponthe functionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special-purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

The following discussion is intended to provide a brief, generaldescription of suitable computing environments in which the system andmethod may be implemented. Although not required, the disclosedembodiments will be described in the general context ofcomputer-executable instructions, such as program modules, beingexecuted by a single computer. In most instances, a “module” can includea software application, but can also be implemented as both software andhardware (i.e., a combination of software and hardware).

Generally, program modules include, but are not limited to, routines,subroutines, software applications, programs, objects, components, datastructures, etc., that perform particular tasks or implement particulardata types and instructions. Moreover, those skilled in the art willappreciate that the disclosed method and system may be practiced withother computer system configurations, such as, for example, hand-helddevices, multi-processor systems, data networks, microprocessor-based orprogrammable consumer electronics, networked PCs, minicomputers,mainframe computers, servers, and the like.

Note that the term module as utilized herein may refer to a collectionof routines and data structures that perform a particular task orimplements a particular data type. Modules may be composed of two parts:an interface, which lists the constants, data types, variable, androutines that can be accessed by other modules or routines, and animplementation, which may be private (accessible only to that module)and which can include source code that actually implements the routinesin the module. The term module may also simply refer to an application,such as a computer program designed to assist in the performance of aspecific task, such as word processing, accounting, inventorymanagement, etc. In some example embodiments, the term “module” may alsorefer to a modular hardware component or a component that is acombination of hardware and software. Examples of modules can includethe various elements discussed and described herein. A module or groupof modules can implement the various elements, blocks, instructions,steps and/or operations described herein.

FIGS. 5-6 are thus intended as examples and not as architecturallimitations of disclosed embodiments. Additionally, such embodiments arenot limited to any particular application or computing or dataprocessing environment. Instead, those skilled in the art willappreciate that the disclosed approach may be advantageously applied toa variety of systems and application software. Moreover, the disclosedembodiments can be embodied on a variety of different computingplatforms.

The embodiments may be an apparatus, a system, a method, and/or acomputer program product. The computer program product may include acomputer readable storage medium (or media) having computer readableprogram instructions thereon for causing a processor to carry outaspects of the present invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing.

A non-exhaustive list of more specific examples of the computer readablestorage medium includes the following: a portable computer diskette, ahard disk, a random access memory (RAM), a read-only memory (ROM), anerasable programmable read-only memory (EPROM or Flash memory), a staticrandom access memory (SRAM), a portable compact disc read-only memory(CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk,a mechanically encoded device such as punch-cards or raised structuresin a groove having instructions recorded thereon, and any suitablecombination of the foregoing. A computer readable storage medium, asused herein, is not to be construed as being transitory signals per se,such as radio waves or other freely propagating electromagnetic waves,electromagnetic waves propagating through a waveguide or othertransmission media (e.g., light pulses passing through a fiber-opticcable), or electrical signals transmitted through a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowcharts and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowcharts and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowcharts and/or block diagram block orblocks.

The flowcharts and block diagrams in the figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowcharts or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustrations, and combinations ofblocks in the block diagrams and/or flowchart illustrations, can beimplemented by special purpose hardware-based systems that perform thespecified functions or acts or carry out combinations of special purposehardware and computer instructions.

It will be appreciated that variations of the above-disclosed and otherfeatures and functions, or alternatives thereof, may be desirablycombined into many other different systems or applications. It will alsobe appreciated that various presently unforeseen or unanticipatedalternatives, modifications, variations or improvements therein may besubsequently made by those skilled in the art which are also intended tobe encompassed by the following claims.

What is claimed is:
 1. A system for measuring a flow of saturated steam,comprising: a temperature sensor that measures a process temperature;and at least one pressure sensor that measures pressure including adifferential pressure and a static pressure, wherein two sets ofmeasurements are used to calculate a flow of saturated steam, wherein afirst set of measurements among the two sets of measurements uses thedifferential pressure and the static pressure to calculate the flow ofsaturated steam and a second set of measurements among the sets ofmeasurements uses the differential pressure and the process temperatureto calculate the flow of saturated steam, wherein the system isconfigured to provide redundant flow measurements with respect to theflow of the saturated steam in case of a failure of either thetemperature sensor or the static pressure sensor.
 2. The system of claim1 wherein a deviation between a flow of the saturated steam ascalculated from the process temperature and the differential pressurecompared to a flow of the saturated steam as calculated from thedifferential pressure and the static pressure provides an indication ofa degradation of at least one of: the temperature sensor and the atleast one pressure sensor.
 3. The system of claim 2 wherein thedeviation comprises an early indicator for calibration of either thetemperature sensor or the at least one pressure sensor.
 4. The system ofclaim 1 wherein a quality status regarding which of the redundant flowmeasurements is output with respect to the flow of the saturated steam.5. The system of claim 1 wherein a quality status is output regarding:the differential pressure and the process temperature measured tocalculate the flow of the saturated steam; and the differential pressureand the static pressure measured to calculate the flow of the saturatedsteam.
 6. The system of claim 1, further comprising: a multi-variabletransmitter; a field mounted device; an RTU (Remote Terminal Unit); aPLC (Programmable Logic Controller); and a DCS (Digital Control System).7. A system for measuring a flow of saturated steam, the systemcomprising: at least one processor; and a non-transitory computer-usablemedium embodying computer program code, the computer-usable mediumcapable of communicating with the at least one processor, the computerprogram code comprising instructions executable by the at least oneprocessor and configured for: measuring a process temperature with atemperature sensor; and measuring with at least one pressure sensorlocated in a pressure meter body, a pressure including a differentialpressure and a static pressure, wherein the temperature sensor and theat least one pressure sensor provide two sets of measurements tocalculate a flow of saturated steam, computing a first set ofmeasurements among the two sets of measurements using the differentialpressure and the static pressure provided by the at least one pressuresensor to calculate a first computed flow of saturated steam, computinga second set of measurements among the two sets of measurements usingthe differential pressure provided by the at least one pressure sensorand the process temperature provided by the temperature sensor tocalculate a second computed flow of saturated steam, comparing anddetermining a deviation between the first computed flow of saturatedsteam and the second computed flow of saturated steam corresponding tothe two sets of measurements, and evaluating the deviation between thefirst and the second flows of saturated steam to determine failure ofeither the temperature sensor or the static pressure sensor, wherein thesystem is configured to provide output redundant first and second flowsof the saturated steam in case of the failure of either the temperaturesensor or the static pressure sensor.
 8. The system of claim 7 whereinthe instructions are further configured for providing an indication of adegradation of at least one of: the temperature sensor and the at leastone pressure sensor, based on the deviation.
 9. The system of claim 8wherein the deviation comprises an early indicator for calibration ofeither the temperature sensor or the at least one pressure sensor. 10.The system of claim 7 wherein a quality status regarding which of theredundant flow measurements is output with respect to the flow of thesaturated steam.
 11. The system of claim 7 wherein a quality status isoutput regarding: the differential pressure and the process temperaturemeasured to calculate the flow of the saturated steam; and thedifferential pressure and the static pressure measured to calculate theflow of the saturated steam.
 12. The system of claim 7, furthercomprising: a multi-variable transmitter; a field mounted device; an RTU(Remote Terminal Unit); a PLC (Programmable Logic Controller); and a DCS(Digital Control System).
 13. A method for measuring a flow of saturatedsteam, comprising the steps of: measuring a process temperature with atemperature sensor; and measuring with at least one pressure sensor, apressure including a differential pressure and a static pressure,wherein two sets of measurements are used to calculate a flow ofsaturated steam, wherein a first set of measurements among the two setsof measurements uses the differential pressure and the static pressureto calculate the flow of saturated steam and a second set ofmeasurements among the sets of measurements uses the differentialpressure and the process temperature to calculate the flow of saturatedsteam, wherein redundant flow measurements are provided with respect tothe flow of the saturated steam in case of a failure of either thetemperature sensor or the static pressure sensor.
 14. The method ofclaim 13 further comprising a step of: determining a deviation between aflow of the saturated steam as calculated from the process temperatureand the differential pressure compared to a flow of the saturated steamas calculated from the differential pressure and the static pressureprovides an indication of a degradation of at least one of: thetemperature sensor and the at least one pressure sensor.
 15. The methodof claim 14 wherein the deviation comprises an early indicator forcalibration of either the temperature sensor or the at least onepressure sensor.
 16. The method of claim 13 further comprising a step ofgenerating a quality status regarding the redundant flow measurementswith respect to the flow of the saturated steam.
 17. The method of claim13 further comprising a step of: generating a quality status regardingthe differential pressure and the process temperature measured tocalculate the flow of the saturated steam.
 18. The method of claim 13further comprising a step of: generating a quality status regarding thedifferential pressure and the static pressure measured to calculate theflow of the saturated steam.
 19. The method of claim 13 furthercomprising a step of: generating a quality status regarding: thedifferential pressure and the process temperature measured to calculatethe flow of the saturated steam; and the differential pressure and thestatic pressure measured to calculate the flow of the saturated steam.20. The method of claim 13 wherein the step of measuring the processtemperature with the temperature sensor and the step of measuring withthe at least one pressure sensor, the pressure including thedifferential pressure and the static pressure, are performed in: amulti-variable transmitter; a field mounted device; an RTU (RemoteTerminal Unit); a PLC (Programmable Logic Controller); or a DCS (DigitalControl System).